I found the New F1 (with the centre weighted metering, microprism+split screen... sorry, I don't know the call letters) to be very bright, but all the Canon's I have used seem to be pretty good. The oldest I have had was an early production EF (no split-prism), and I suppose it was a touch dimmer than the New F1, but not noticably so. I think with the cameras like FTb, given their prices and age, you kind of have to see their shortcomings as their charms. If you want to improve on them, its really difficult to justify modifications financially. I am sure this proposed operation would cost a lot more than getting an EF or an orignal F1 (the reason I mention those is because you mentioned MLU as something you appreciate, understandably). Then again, I understand there is a way to fit a new screen to almost anything, if you have the money - so its a matter of how dear the little FT is to you.
Peter.